Yarn brake



G. FRANZEN YARN BRAKE Nov. 1.4, 1967 Filed June 2. 1965 lFig. l

United States Patent O 7 claims. (ci. 242-149) ABSTRACT F THE DISCLOSURE A yielding resilient brake comprising a housing providing entry and exit ends for the yarn and containing a braking member, co-axially aligned annular seating members in said housing between which seating members said braking member is disposed and with which said member produces a iirst stage of braking in co-operation with the seating member at the entry end and a second stage of braking with the seating member at the exit end, the said braking member being a rigid member and that one of said annular seating members co-operating therewith at lthe exit end being yieldingly slidable supported in the housing for movement relatively to the other seating member in the direction of travel of the yarn. j

The yarn brake has an axially magnetised annular permanent magnet dis-placeable with the said yielding annular seating member and a further axially magnetised annular permanent magnet which by magnetic action in co-operation with said rst-mentioned magnet holds the said yielding annular seating in place while permitting yielding sliding movement thereof under pressure of the yarn in said housing.

The foregoing abstract is not intended to be a comprehensive discussion of all of the principles, possible modes or applications of the invention disclosed iu this document and should not be used to interpret the scope of the claims which appear at the end of this specilication.

The invention relates to a yieldingly resilient yarn brake. Such yarn brakes comprising a braking member with spherical braking surfaces and coaxially aligned annular seatings for the spherical braking surfaces are known to the art.

In such yarn brakes the yarn travels between the spherical surfaces and the annular seatings and is frictionally braked between them. The braking force is generated by a spring contained in a sleeve consisting of telescopically interposed parts. A braking member of this kind has the shape of a cylinder with spherical ends. The spherical ends are urged outwards against the annular seatings by the spring contained inside the cylinder.

Likewise known are constructions of yieldingly resilient yarn brakes in which two balls are urged into the coaxially aligned annular seatings by an interposed coil spring.

In all these constructions the braking forces are more or less uncontrolled so that the tension the brake is intended to maintain in the yarn is non-uniform, a result which for instance in the operation of double twist spindles leads to fluctuations in the tension of the ballooning yarn.

It is the object of the present invention to eliminate the drawbacks of known devices and to provide a yarn brake which generates substantially more uniform controllable braking forces, and which therefore, when used in conjunction with double twist spindles, provides the necessai,I conditions for as uniform as possible a behaviour of the balloon. This in turn ensures greater twist- 3,352,510 Patented Nov. 14, 1967 ing accuracy and reduces the number of yarn breakages, though facilitating the threading of the yarn.

According to the invention the problem is solved by providing an annular seating that is yieldable in the direction of travel of the yarn at the end where the yarn leaves the brake, whereas the braking member itself is a rigid member. The proposed arrangement has the advantage that the yielding parts of the brake can move only in the direction of travel of the yarn and that there are no parts in the brake which are forced to yield contrary to the direction of travel of the yarn. In the known yarn brakes in which this is the case the braking effects abruptly change when parts of the brake respond by moving contrary to the direction of travel of the yarn. A brake constructed as proposed by the present invention resiliently yields to the diierent thicknesses of the yarn and causes neither blockages nor sudden and abrupt changes in the tensioning force.

The yielding annular seating may be supported by a coil spring. Alternatively, an axially magnetised annular permanent magnet may be provided at the yielding annular seating for co-operation with a fixed likewise axially magnetised annular counter-magnet.

The braking member may be a ball. However, it i's preferred to provide a cylindrical member with spherical ends. In order to reduce the mass of the braking membr it is preferred that it should be hollow. Instead of spherical ends coned surfaces may be provided, defined by straight or curved generatrices. The annular seatings may have coned surfaces or surfaces that are arcuately curved (convex or concave).

In order to permit the braking force to be adjustably controlled, the fixed annular seating may be axially adjustable. Alternatively, the bias of the spring supporting the yielding annular seating may be adjustable or the spacing of the permanent annular magnets supporting the seating may be controllably variable. By these means, severally or in combination, the braking force of the brake may be adjustably varied within a very wide range.

The drawings illustrate two preferred embodiments of the invention, FIG. l illustrating one embodiment and FIG. 2 an alternative embodiment of the invention and both in vertical axial sections. The illustrated yarn brakes are suitable for double twist spindles and are located in the region of the hollow interior of the spindle.

FIG. l shows the bottom end 1 of the entry tube of the double twist spindle. A specially shaped member 2 is screwed on to the end of tube 1 and serves to support the annular seating 3. The shaped member 2 is contained in a sleeve 4 which also slidably contains a second shaped member 5 carrying the second annular seating 6. The braking member 7 is contained in the space between the two seatings. In the illustrated example the braking member has the form of a hollow cylinder with spherical ends. These spherical ends bear against the annular seatings 8 and 9.

The lower shaped member 5 which is slidably contained in sleeve 4 is urged by a coil spring 10 against the braking member 7. The yarn 11 which runs into the double twist spindle enters tube 1 and then travels first between the annular seating 8 and the spherical end of the braking member 7, then between the annular seating 9 and the other spherical end of the braking member and out through the extension 12 of the shaped member 5. It will be readily understood that any non-uniformity in the yarn, such as a knot, thickening or the like, causes the braking member 7 to yield in the direction of travel of the yarn because annular seating 6 and its carrier 5 are resiliently supported by spring 10. In order to adjust the braking force the shaped member 2 may be provided with a pin 13 adapted to engage slots 14 of different depths and thereby to extend or contract the space available for the reception of the braking member 7, to vcompress spring to a greater or lesser degree. The engagement of the screw with the bottom of the slot limits the movement of the member 2 into the housing and it can be retained by its own weight. The bias of spring 10 can lthus be controllably preadjusted. Alternatively, the spring retaining ring may be arranged to be screwed an `adjustable distance into sleeve 4. Both arrangements may be simultaneously provided in which case there is considerable latitude for adjusting the spring bias.

=FIG. 2 illustrates an arrangement which Vis generally very similar to that shown in FIG. 1. The only difference is that for supporting the annular seating 6 an axially magnetised annular permanent magnet 16 is provided, which is secured inside the shaped member 5. The annular permanent countermagnet 17 which is likewise axially magnetised is located in sleeve 4, and the magnetisation ofthe two magnets 16 and 17 is such that like poles face each other. This arrangement likewise yieldingly supports the annular seating 6. The thrust force can be adjusted by changing the relative spacing of the two magnets 16 and `17. Any conventional vspacing means such as nonmagnetic shims will serve for this purpose. By suitably selecting the roughness of the braking members, for instance by the `choice of appropriate materials, the braking force of the brake can 'likewise be changed.

What I claimed is: A

1. A yielding resilient brake comprising'a housing providing entry and exit ends for the yarn and containing a braking member, co-axially aligned annular seating members in said housing between which seating members said braking member is disposed and with which said braking Y member produces a rst stage of braking in co-opera'tion with the seating member at the entry end and a second stage of braking Withe seating member at the exit end,

the said braking member being a rigid member and that one of said annular seatingmembers co-operating there-l with at the exit end being yieldingly slidable supported in the housing for movement relatively to the other-seating member in the direction of travel of the yarn. j 2. A yarn brake according to claim 1, having an axially magnetised annular permanent magnet displaceable kwith the said yielding annular seating member and a further axially magnetised annular permanent magnet which Yby magnetic action in co-operation with said rst mentioned magnet holds the said yielding annular seating in place while permitting yielding sliding movement thereof under pressure of the yarn in said housing.

3. A yarn brake according to claim 2, havingmeans for varying the distance between said permanent magnets. 4. A yarn brake according to'claim 1, in which the said yielding annular seating is supported by a coil spring. 5. A yarn brake according to claim 1, in which the said braking member is a substantially hollow cylinder with spherical ends. v

6. A yarn brake according to 'claim 1, in which the said annular seating at the entry end of the yarn is axially adjustable.

, 7. A yarn brake according to claim 1 having a spring for Vsupporting the yielding annular seating at the exit end of the yarn and means for adjustably biasing said spring.

References Cited UNITED STATES PATENTS 1,826,354 10/1931 Lenk 242-149 2,281,204 4/1942 Ray-mond 57-58;86 x

2,870,596 1/1959 vibber 57-5886 X FOREIGN PATENTS 1,246,080 10/1960 France.

STANLEY N. GllREATI-L Primary Examiner. 

1. A YIELDING RESILIENT BRAKE COMPRISING A HOUSING PROVIDING ENTRY AND EXIT END FOR THE YARN AND CONTAINING A BRAKING MEMBER, CO-AXIALLY ALIGNED ANNULAR SEATING MEMBERS IN SAID HOUSING BETWEEN WHICH SEATING MEMBERS SAID BRAKING MEMBER IS DISPOSED AND WITH WHICH SAID BRAKING MEMBER PRODUCES A FIRST STAGE OF BRAKING IN CO-OPERATION WITH THE SEATING MEMBER AT THE ENTRY END AND A SECOND STAGE OF BRAKING WITH THE SEATING MEMBER AT THE EXIT END, THE SAID BRAKING MEMBER BEING A RIGID MEMBER AND THAT ONE OF SAID ANNULAR SEATING MEMBERS CO-OPERATING THEREWITH AT THE EXIT END BEING YIELDINGLY SLIDABLE SUPPORTED IN THE HOUSING FOR MOVEMENT RELATIVELY TO THE OTHER SEATING MEMBER IN THE DIRECTION OF TRAVEL OF THE YARN. 